Children from disadvantaged backgrounds face stressors associated with increased risk for compromised health. The 2003 National Sleep Disorders Research Plan acknowledges that: (a) low socioeconomic status is associated with diminished opportunity for adequate sleep and environmental conditions preventing good sleep quality and (b) the adverse impact of race/ethnicity and socioeconomic status on health outcomes may be mediated by decrements in sleep. Prior research has not fully investigated specific mechanisms (e.g., family structure, poverty status, receipt of social services) through which racial minorities and socioeconomically disadvantaged children experience poorer sleep. To date, little-if-any data on such relationships are available in young children, especially those from disadvantaged backgrounds who are at highest risk for adverse developmental outcomes. This research focuses on caregiver-controlled sleep-related behaviors (e.g., bedtime routine and its components, regularity of bedtime, co-sleeping) and their associations with health outcomes in socioeconomically disadvantaged young children. We propose to analyze two longitudinal, national, large-sample datasets, the Fragile Families and Child Wellbeing Study (FFCW;n~3000) and the Early Head Start Study (EHS;n~1900). Both datasets provide detailed, repeated measures of sleep-related behaviors, socioeconomic family characteristics, early childhood developmental/biomedical status, and children's behavioral, cognitive, and physical health outcomes. We will address the following aims: Caregiver-Controlled Sleep-Related Behaviors Aim 1: To describe caregiver-controlled sleep-related behaviors in disadvantaged children at ages 1, 2, 3, and 5 years old and how these behaviors change across early development. Social and Economic Predictors of Caregiver-Controlled Sleep-Related Behaviors Aim 2: To examine whether socioeconomic disadvantage (e.g., low maternal education, household poverty, single-mother households) explains known variation by race and ethnicity in caregiver-controlled sleep-related behaviors in children ages 1-5. Aim 3: To investigate whether receipt of social services (e.g., child enrolled in an Early Head Start Center or receiving public assistance, home visits, case management) is associated with increased use of caregiver- controlled sleep-related behaviors in children ages 1-5, net of adjustment for socioeconomic disadvantage and other family and household characteristics (e.g. race, family size). Health Outcomes and Caregiver-Controlled Sleep-Related Behaviors Aim 4: To assess the extent to which caregiver-controlled sleep-related behaviors at ages 1, 2, and 3 are associated with specific behavioral, cognitive, and physical health outcomes at age 5, net of adjustment for prior child characteristics, socioeconomic disadvantage, and other family and household characteristics. PUBLIC HEALTH RELEVANCE: The proposed research focuses on caregiver-controlled sleep-related behaviors (e.g., bedtime routine and its components, regularity of bedtime, co-sleeping) and their associations with behavioral, cognitive, and physical health outcomes in socioeconomically disadvantaged young children. Understanding these relationships will identify target populations for intervention and inform development of culturally- sensitive programs to promote sleep quality and child wellbeing.